solution 

Characteristics

• Soluble. the ability of a substance to be dissolved by a solvent

* Insoluble: the ability of a substance to NOT be dissolved by a solvent.

• Immiscible: two liquids that can be mixed together but separate shortly after you cease miring them

• Miscible two liquids that are soluble in each other

Solvation

  • The process of surrounding solute particles with solvent particles to form a solution.

  • Occurs only where and when the solute and solvent particles come in contact with each other

  • When the attractive forces between the solute and solvent particles is greater than the attractive forces between particles of the solute

  • Heat of solution: overall energy change that occurs during the solvation process

  • If energy is released: EXOTHERMIC (gets warmer)

  • If energy is absorbed: ENDOTHERMIC (gets colder)

actors that affect rate of Solvation

Three common ways to increase rate of solvation

• Agitate the mixture (stirring/sonication)

Moves dissolved particles away so more new collisions can occur

Increasing the surface area of the solute

Break the solute into smaller pieces

Increasing the temperature of the solvent

Increases kinetic energy of the particles, causing them to move around more rapidiy which increases the frequency of collisions

Crystallization

  • Simply, the opposite of solvation.

  • The separation of solute and solvent back into crystals, solids, original forms, etc

  • Crystallization can occur during solvation when solvated particles (the dissolved solute) begin colliding with the surface of the original solid solute.

Solubility

Refers to maximum amount of solute that will dissolve in a given amount of solvent at a specific temperature and pressure.

• Expressed as grams of solute per 100g of solvent

Depending on the amount of sotute present, the rates of solvation and crystallization may eventually equalize

Saturated solutions: Contains the maximum amount of dissolved solute for a given amount of solvent at a specific temperature and pressure

Unsaturated solutions: contains less dissolved solute for a given temperature and pressure than a saturated solutions.

Factors that affect solubility

  • Pressure affects the solubility of gaseous solutes and gaseous solutions

  • Soda going flat if left open

Solubility of a solute depends on the nature of the solute and solvent.

• Temperature affects the solubility of all substances

Supersaturated solutions

Contains more dissolved solute than a saturated solution at the same temperature

• Very unstable

Sodium Acetate

Factors Affecting Solubility

Temperature

Higher temp → increase solubility of solids and liquids

Higher temp → decrease solubility of gases

Pressure

Higher pressure → increase solubility of gases

  • NO EFFECT ON SOLIDS OR LIQUIDS
    Polarity of molecules: "Like dissolves like"

  • Polar solvents dissolve polar or ionic solutes
    Nonpolar solvents dissolve only nopolar solutes

Solubility: How much solute dissolves per given amount of solvent

  • Ex: 80. g of KNO3 can dissolve in 100 g of H20 at 50 °C

  • What is the solubility of sodium nitrate (NaNO,) at 30 °C?

Characteristics of Solutions

  • Soluble: Ability of a substance to be dissolved by a solvent.

  • Insoluble: Substance that cannot be dissolved by a solvent.

  • Miscible: Two liquids that are soluble in each other.

  • Immiscible: Two liquids that can be mixed but separate shortly after mixing.

Solvation: The process of surrounding solute particles with solvent particles to form a solution. It occurs where solute and solvent particles contact each other. Energy changes during solvation can be:

  • Exothermic: Energy is released (solution gets warmer).

  • Endothermic: Energy is absorbed (solution gets colder).

Factors Affecting Rate of Solvation:

  1. Agitation (stirring)

  2. Increasing surface area of solute (breaking it into smaller pieces).

  3. Increasing temperature of solvent (increases kinetic energy and collision frequency).

Crystallization: Opposite of solvation; involves the separation of solute and solvent back into their original forms. Can occur when solvated particles collide with solid solute.

Solubility: Maximum amount of solute that will dissolve in a specific amount of solvent at particular temperature and pressure. Expressed in grams of solute per 100g of solvent.

  • Saturated solutions: Maximum dissolved solute.

  • Unsaturated solutions: Less dissolved solute than saturation.

  • Supersaturated solutions: More dissolved solute than saturation at the same temperature (unstable).

Factors Affecting Solubility:

  1. Temperature: Higher temperature increases solubility of solids and liquids, decreases solubility of gases.

  2. Pressure: Higher pressure increases solubility of gases (no effect on solids/liquids).

  3. Polarity: "Like dissolves like"; polar solvents dissolve polar/ionic solutes and nonpolar solvents dissolve nonpolar solutes.

Example: 80 g of KNO3 dissolves in 100 g of H2O at 50 °C.